This invention relates to compression molding equipment and more particularly to a closure assembly for a press used for mounting metallurgical specimens in a plastic mount.
Metal specimens which are to be examined metallographically are mounted in a plastic sample or mount wherein the specimen is embedded in the plastic with one side exposed for examination. The sample is prepared by placing the specimen in a molding press, adding the plastic mounting material and curing the plastic under pressure with heat.
In the past, certain problems have been encountered with devices of this type. For example, in prior closure members which were threadedly inserted into the mold, vibration of certain portions of the press would result in the upper cap member shaking loose and because of the substantial pressure in the mold would, on occasion, become completely loosened from its threaded connection and fly up and hit the ceiling. In addition, the tight insertion of a closure member into the upper end of the mold would require the use of some independent tool, such as a wrench, to tighten the closure member or to loosen it when the molding operation was completed. These conditions required a search for some better construction to improve the closure member and molding machine as a whole.